Integrated circuit package serves to provide protection to integrated circuits through encapsulating the integrated circuit die. Connection of the integrated circuit package to a printed circuit requires an integrated circuit substrate which is also part of the integrated circuit package.
Photoimageable dielectric, PID materials are applied in integrated circuit substrates to enhance the performance of the substrate as they possess compatible properties for integrated circuits such as low dielectric constant, low moisture absorption and good compliance to stress. Furthermore, it is also an affordable material and has a less complex manufacturing process. An example of such PID application in integrated circuit substrate is described in prior art U.S. Pat. No. 5,709,979 where the photoimageable dielectric material is utilized as the base dielectric substrate of a printed wiring board. The printed wiring board comprises a conductive layer which is patterned to form a circuit pattern on a first side of the base substrate. After that, at least one aperture in a second side of the base substrate is fabricated by imaging and developing the photoimageable dielectric material. The use of the photoimageable dielectric material in this prior art improves the resolution and registration precision of access apertures and through holes.
The incorporation of photoimagineable dielectric material in a capacitive substrate is also disclosed in prior art US20070010064 where the method of forming the capacitive substrate involves printing the photoimagineable dielectric layer onto a conductor and fabricating thru-holes to couple selected elements within the substrate for forming at least two capacitors as internal elements of the substrate which defines an electrical assembly.
With dissimilar element arrangements, features and functions from the abovementioned prior arts, the present invention is an integrated circuit substrate containing a conductive base that utilizes the photoimageable dielectric material for guiding the deposition of the patterned conductive layer on the base, and contributing to the performance enhancement of the substrate.